Quinclorac-habituation of bean (Phaseolus vulgaris) cultured cells is related to an increase in their antioxidant capacity

7 p.The habituation of bean cells to quinclorac did not rely on cell wall modifications, contrary to what it was previously observed for the well-known cellulose biosynthesis inhibitors dichlobenil or isoxaben. The aim of the present study was to investigate whether or not the bean cells habituation to quinclorac is related to an enhancement of antioxidant activities involved in the scavenging capacity of reactive oxygen species. Treating non-habituated bean calluses with 10 μM quinclorac reduced the relative growth rate and induced a two-fold increase in lipid peroxidation. However, the exposition of quinclorac-habituated cells to a concentration of quinclorac up to 30 μM neither affected their growth rate nor increased their lipid peroxidation levels. Quinclorac-habituated calluses had significantly higher constitutive levels of three antioxidant activities (class-III peroxidase, glutathione reductase, and superoxide dismutase) than those observed in non-habituated calluses, and the treatment of habituated calluses with 30 μM quinclorac significantly increased the level of class III-peroxidase and superoxide dismutase. The results reported here indicate that the process of habituation to quinclorac in bean callus-cultured cells is related, at least partially, to the development of a stable antioxidant capacity that enables them to cope with the oxidative stress caused by quinclorac. Class-III peroxidase and superoxide dismutase activities could play a major role in the quinclorac-habituation. Changes in the antioxidant status of bean cells were stable, since the increase in the antioxidant activities were maintained in quinclorac-dehabituated cellsS

Early habituation of maize (Zea mays) suspension-cultured cells to 2,6- diclorobenzonitrile is associated with the enhancement of antioxidant status

30 p.The cellulose biosynthesis inhibitor 2,6-diclorobenzonitrile (DCB) has been widely used to gain insights into cell wall composition and architecture. Studies of changes occurring during incipient habituation to DCB can provide information on early cell mechanisms leading to cope with DCB-induced stress. In this context, maize cultured cells with a reduced amount of cellulose were obtained by stepwise habituation to low DCB concentrations. The results reported here attempt to elucidate the putative role of an antioxidant strategy during incipient habituation. The short-term exposure to DCB of non-habituated maize cultured cells induced a substantial increase in oxidative damage. Concomitantly, short-term treated cells presented an increase in class III peroxidase and glutathione S-transferase activities and total glutathione content. Maize cells habituated to 0.3 – 1 μM DCB (incipient habituation) were characterised by a reduction in the relative cell growth rate, an enhancement of ascorbate peroxidase and class III peroxidase activities, and a net increment in total glutathione content. Moreover, these cell lines showed increased levels of glutathione S-transferase activity. Changes in antioxidant/detoxifying status enabled 0.3 and 0.5 μM DCB-habituated cells to control lipid peroxidation levels, but this was not the case of maize cells habituated to 1 μM DCB, which despite showing an increased antioxidant capacity were not capable of reducing the oxidative damage to control levels. The results reported here confirm that exposure and incipient habituation of maize cells to DCB are associated with an enhancement in antioxidant/detoxifying activities which could play a role in incipient DCB habituation of maize cultured cellsS

Manganese transporter protein MntH is required for virulence of Xylophilus ampelinus, the causal agent of bacterial necrosis in grapevine

This journal is published by Hindawi as part of a publishing collaboration with the Australian Society of Viticulture and Oenology. It is a fully open access journal produced under the Hindawi and Wiley brands[EN] Background and Aims: The aim of this study is to identify proteins involved in the pathogenicity/virulence of Xylophilus ampelinus. Characterisation of these proteins could provide new insights into putative targets for controlling bacterial necrosis in grapevines. Methods and Results: Transposon insertion mutagenesis was used to isolate X. ampelinus mutants exhibiting an altered virulence. Characterisation of one of the avirulent mutants revealed the insertion of a transposon into the mntH gene encoding the major manganese transporter. Virulence tests on grapevine leaves clearly showed that the virulence of these mutants was significantly reduced. Phenotypic analysis of an mntH mutant indicated that the MntH protein is a Mn++ transporter but that MntH does not play a significant role in the transport of Fe++ or Cu++. The MntH mutants exhibited an increased sensitivity to hydrogen peroxide, although catalase and superoxide dismutase activities were not significantly affected. Conclusion: The MntH protein plays a significant role in the virulence of X. ampelinus. Significance of the Study: This is the first report showing that transposon mutagenesis is an effective strategy for the isolation of X. ampelinus mutants. It is also the first report characterising a gene encoding a protein involved in virulence in this grapevine pathogenSIThis work was financed by a Research Contract sponsored by Bodegas Vega Sicilia S.A. (Valbuena de Duero, Valladolid, Spain

Determination of Partition Coefficients of Selected Model Migrants between Polyethylene and Polypropylene and Nanocomposite Polypropylene

Studies on nanoparticles have focused the attention of the researchers because they can produce nanocomposites that exhibit unexpected hybrid properties. Polymeric materials are commonly used in food packaging, but from the standpoint of food safety, one of the main concerns on the use of these materials is the potential migration of low molecular substances from the packaging into the food. The key parameters of this phenomenon are the diffusion and partition coefficients. Studies on migration from food packaging with nanomaterials are very scarce. This study is focused on the determination of partition coefficients of different model migrants between the low-density polyethylene (LDPE) and polypropylene (PP) and between LDPE and nanocomposite polypropylene (naPP). The results show that the incorporation of nanoparticles in polypropylene increases the mass transport of model migrants from LDPE to naPP. This quantity of migrants absorbed into PP and naPP depends partially on the nature of the polymer and slightly on the chemical features of the migrant. Relation () between partition coefficient and partition coefficient at 60°C and 80°C shows that only BHT at 60°C has a less than 1. On the other hand, bisphenol A has the highest with approximately 50 times more.The study was financially supported by the Xunta de Galicia (Project no. INCITE08PXIB203096). R. Sendon is grateful to the “Parga Pondal” Program financed by “Consellería de Innovación e Industria, Xunta de Galicia” for her postdoctoral contractS

El profesor como práctico reflexivo en una cultura de colaboración

El marco teórico ha reconsiderado el curriculum en una cultura de colaboracion reflexiva en un colegio, investigdndolo mediante un paradigma de pensamiento. El proceso se ha caracterizado por: (a) investigadores como asesores extemos; (b) autorrevisión de la practica educativa; (c) estudio de caso como metodología de indagación; (d) técnicas etno‐gráflcas de recolección de datos; (e) programas de ordenador (AQUAD) para analizar datos; (f) ciclo refiexivo para reconstruir la práctica; y (g) dossier personal: esquemas, viñetas, etc. Los hallazgos muestran: (a) desarrollo de proceso interactivo de colaboracion universidad‐es‐cuela; (b) grados de implication curricular; (c) cambio instruccional de profesoras; (d) movilización de talentos y valores de las 29 profesoras: (i) diadas para reflexionar; (ii) interpretation de la enseñanza ante colegas; (in) diseño de materiales curriculares; y (iv) enseñanza de compañeras. Finalmente, (e) mejora de la comunidad de aprendizaje. El estudio concluye: (a) el conocimiento práctico pedagógico muestra diversidad de teorías subjetivas para diseñar actión; y (b) la teoría fundamentada manifiesta enseñanza basada en una cultura de colaboración reflexiva.The aim was the reconstruction of a school curriculum in reflective teaching situations within a co-operative culture. Two working assumptions were considered: (a) teacher development was based on teacher thinking and (b) school organisation followed a co-operative culture paradigm. The process features were: (a) university team consisted of external advisers; (b) school curriculum and classroom instruction were reviewed by school teachers; (c) case study as a research approach; (d) ethnographic techniques to collect data; (e) data analysis by a computer program; (f) teachers' reflective cycle to reconstruct practice; and (g) teachers' portfolios: narrative vignettes, etc. Findings showed: (a) a collaborative process school-university; (b) teachers' thinking and attitudinal change; (c) mobilisation of teachers' talents and values to work together: (i) teacher dyads to reflect on teaching; (ii) advisers' writing narrative vignettes; (Hi) collegial coaching; and (iv) curriculum materials designed by teachers. Two conclusions can be accepted: (a) teachers' pedagogical practical knowledge showed diversity of their implicit theories to design action; and (b) teachers' grounded theory confirmed that the educational action was based on a co-operative and reflective culture.Investigacion subvencionada por el CIDE (Centro de Investigacion y Documentacion Educativa) del MEC (Ministerio de Education y Ciencia)

Postural orthostatic tachycardia syndrome and other related dysautonomic disorders after SARS-CoV-2 infection and after COVID-19 messenger RNA vaccination

The COVID-19 pandemic has caused a challenge for our society due to the post-acute sequelae of the disease. Persistent symptoms and long-term multiorgan complications, known as post-acute COVID-19 syndrome, can occur beyond 4 weeks from the onset of the COVID-19 infection. Postural orthostatic tachycardia syndrome (POTS) is considered a variety of dysautonomia, which is characterized by chronic symptoms that occur with standing and a sustained increase in heart rate, without orthostatic hypotension. POTS can lead to debilitating symptoms, significant disability, and impaired quality of life. In this narrative review, the etiopathogenic basis, epidemiology, clinical manifestations, diagnosis, treatment, prognosis, and socioeconomic impact of POTS, as well as other related dysautonomic disorders, after COVID-19 infection and SARS-CoV-2 postvaccination, were discussed. After a search conducted in March 2023, a total of 89 relevant articles were selected from the PubMed, Google Scholar, and Web of Science databases. The review highlights the importance of recognizing and managing POTS after COVID-19 infection and vaccination, and the approach to autonomic disorders should be known by all specialists in different medical areas. The diagnosis of POTS requires a comprehensive clinical assessment, including a detailed medical history, physical examination, orthostatic vital signs, and autonomic function tests. The treatment of POTS after COVID-19 infection or vaccination is mainly focused on lifestyle modifications, such as increased fluid and salt intake, exercise, and graduated compression stockings. Pharmacotherapy, such as beta-blockers, fludrocortisone, midodrine, and ivabradine, may also be used in selected cases. Further research is needed to understand the underlying mechanisms, risk factors, and optimal treatment strategies for this complication

Autoantibodies against the immunodominant sCha epitope discriminate the risk of sudden death in chronic Chagas cardiomyopathy

In Chagas disease (ChD) caused by Trypanosoma cruzi, new biomarkers to predict chronic cardiac pathology are urgently needed. Previous studies in chagasic patients with mild symptomatology showed that antibodies against the immunodominant R3 epitope of sCha, a fragment of the human basic helix-loop-helix transcription factor like 5, correlated with cardiac pathology. To validate sCha as a biomarker and to understand the origin of anti-sCha antibodies, we conducted a multicenter study with several cohorts of chagasic patients with severe cardiac symptomatology. We found that levels of antibodies against sCha discriminated the high risk of sudden death, indicating they could be useful for ChD prognosis. We investigated the origin of the antibodies and performed an alanine scan of the R3 epitope. We identified a minimal epitope MRQLD, and a BLAST search retrieved several T. cruzi antigens. Five of the hits had known or putative functions, of which phosphonopyruvate decarboxylase showed the highest cross-reactivity with sCha, confirming the role of molecular mimicry in the development of anti-sCha antibodies. Altogether, we demonstrate that the development of antibodies against sCha, which originated by molecular mimicry with T. cruzi antigens, could discriminate electrocardiographic alterations associated with a high risk of sudden death.Ministerio de Economía y competitividad and Fondo Europeo de Desarrollo Regional (SAF2015-63868-R (MINECO/FEDER) to N.G., and SAF2016-75988-R (MINECO/FEDER) to M.F.); Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación and Fondo Europeo de Desarrollo Regional (PGC2018-096132-BI00 (MICINN/FEDER) to N.G.); Universidad Autónoma de Madrid-Banco de Santander Inter-University Cooperation Grant with Latin América (CEAL-AL/2015-12 to N.G.); Red de Investigación de Centros de Enfermedades Tropicales (RICET RD12/0018/0004 to M.F.); and Comunidad de Madrid (S-2010/BMD-2332 to M.F.). CBMSO institutional grants from Fundación Ramón Areces and Banco de Santande